The U.S. Diplomatic Security Service (DSS) is the federal law enforcement arm of the United States Department of State. The majority of its Special Agents are members of the Foreign Service and federal law enforcement agents at the same time, making them unique

The United States Marshals Service (USMS) is a United States federal law enforcement agency within the United States Department of Justice. Although the Marshals Service itself dates only to 1969, the office of U.S. Marshal is the oldest federal law enforcement office in the United States.